/**************************************************************************
 *
 * Copyright 2011 Jose Fonseca
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 **************************************************************************/

/*
 * String manipulation.
 */

#ifndef _OS_STRING_HPP_
#define _OS_STRING_HPP_


#include <assert.h>
#include <stdarg.h>
#include <stdio.h>
#include <stddef.h>

#include <string>
#include <fstream>
#include <sstream>
#ifndef _WIN32
#include <unistd.h>
#endif

#ifdef __MINGW32__
// Some versions of MinGW are missing _vscprintf's declaration, although they
// still provide the symbol in the import library.
extern "C" _CRTIMP int _vscprintf(const char *format, va_list argptr);
#endif

#ifndef va_copy
#ifdef __va_copy
#define va_copy(dest, src) __va_copy((dest), (src))
#else
#define va_copy(dest, src) (dest) = (src)
#endif
#endif

#include <vector>

#include "os.hpp"


#ifdef _WIN32
#define OS_DIR_SEP '\\'
#else /* !_WIN32 */
#define OS_DIR_SEP '/'
#endif /* !_WIN32 */


namespace os {


/**
 * Vector based zero-terminate string, suitable for passing strings or paths
 * to/from OS calls.
 */
class String {
protected:
    typedef std::vector<char> Buffer;

    /**
     * The buffer's last element is always the '\0' character, therefore the
     * buffer must never be empty.
     */
    Buffer buffer;

    Buffer::iterator find(char c) {
        Buffer::iterator it = buffer.begin();
        assert(it != buffer.end());
        while (it != buffer.end()) {
            if (*it == c) {
                return it;
            }
            ++it;
        }
        return buffer.end();
    }

    Buffer::iterator rfind(char c) {
        Buffer::iterator it = buffer.end();

        // Skip trailing '\0'
        assert(it != buffer.begin());
        --it;
        assert(*it == '\0');

        while (it != buffer.begin()) {
            --it;
            if (*it == c) {
                return it;
            }
        }

        return buffer.end();
    }

    String(size_t size) :
        buffer(size) {
    }

    char *buf(void) {
        return &buffer[0];
    }

    inline bool
    isSep(char c) {
        if (c == '/') {
            return true;
        }
#ifdef _WIN32
        if (c == '\\') {
            return true;
        }
#endif
        return false;
    }

    Buffer::iterator rfindSep(void) {
        Buffer::iterator it = buffer.end();

        // Skip trailing '\0'
        assert(it != buffer.begin());
        --it;
        assert(*it == '\0');

        // Skip trailing separators
        while (it != buffer.begin()) {
            --it;
            if (isSep(*it)) {
                // Halt if find the root
                if (it == buffer.begin()) {
                    return it;
                }
            } else {
                break;
            }
        }

        // Advance to the last separator
        while (it != buffer.begin()) {
            --it;
            if (isSep(*it)) {
                return it;
            }
        }

        return buffer.end();
    }


public:

    /*
     * Constructors
     */

    String() {
        buffer.push_back(0);
    }

    String(const char *s) :
        buffer(s, s + strlen(s) + 1)
    {}

    String(const String &other) :
        buffer(other.buffer)
    {}

    template <class InputIterator>
    String(InputIterator first, InputIterator last) :
        buffer(first, last)
    {
        buffer.push_back(0);
    }

    /**
     * From a printf-like format string
     */
    static String
    format(const char *format, ...)
#ifdef __GNUC__
    __attribute__ ((format (printf, 1, 2)))
#endif
    {

        va_list args;

        va_start(args, format);

        int length;
        va_list args_copy;
        va_copy(args_copy, args);
#ifdef _WIN32
        /* We need to use _vscprintf to calculate the length as vsnprintf returns -1
         * if the number of characters to write is greater than count.
         */
        length = _vscprintf(format, args_copy);
#else
        char dummy;
        length = vsnprintf(&dummy, sizeof dummy, format, args_copy);
#endif
        va_end(args_copy);

        assert(length >= 0);
        size_t size = length + 1;

        String path(size);

        vsnprintf(path.buf(), size, format, args);
        va_end(args);

        return path;
    }

    /*
     * Conversion to ordinary C strings.
     */

    const char *str(void) const {
        assert(buffer.back() == 0);
        return &buffer[0];
    }

    operator const char *(void) const {
        return str();
    }

    /*
     * Iterators
     */

    typedef Buffer::const_iterator const_iterator;
    typedef Buffer::iterator iterator;

    const_iterator begin(void) const {
        return buffer.begin();
    }

    iterator begin(void) {
        return buffer.begin();
    }

    const_iterator end(void) const {
        const_iterator it = buffer.end();
        assert(it != buffer.begin());
        --it; // skip null
        return it;
    }

    iterator end(void) {
        iterator it = buffer.end();
        assert(it != buffer.begin());
        --it; // skip null
        return it;
    }

    /*
     * Operations
     */

    void insert(iterator position, char c) {
        buffer.insert(position, c);
    }

    template <class InputIterator>
    void insert(iterator position, InputIterator first, InputIterator last) {
        buffer.insert(position, first, last);
    }

    void insert(iterator position, const char *s) {
        assert(s);
        insert(position, s, s + strlen(s));
    }

    void insert(iterator position, const String & other) {
        insert(position, other.begin(), other.end());
    }

    void append(char c) {
        insert(end(), c);
    }

    template <class InputIterator>
    void append(InputIterator first, InputIterator last) {
        insert(end(), first, last);
    }

    void append(const char *s) {
        insert(end(), s);
    }

    void append(const String & other) {
        insert(end(), other);
    }

    char *buf(size_t size) {
        buffer.resize(size);
        return &buffer[0];
    }

    size_t length(void) const {
        size_t size = buffer.size();
        assert(size > 0);
        assert(buffer[size - 1] == 0);
        return size - 1;
    }

    void truncate(size_t length) {
        assert(length < buffer.size());
        buffer[length] = 0;
        buffer.resize(length + 1);
    }

    void truncate(void) {
        truncate(strlen(str()));
    }


    /*
     * Path manipulation
     */

    bool
    exists(void) const;

    /* Trim directory (leaving base filename).
     */
    void trimDirectory(void) {
        iterator sep = rfindSep();
        if (sep != buffer.end()) {
            buffer.erase(buffer.begin(), sep + 1);
        }
    }

    /* Trim filename component (leaving containing directory).
     *
     * - trailing separators are ignored
     * - a path with no separator at all yields "."
     * - a path consisting of just the root directory is left unchanged
     */
    void trimFilename(void) {
        iterator sep = rfindSep();

        // No separator found, so return '.'
        if (sep == buffer.end()) {
            buffer.resize(2);
            buffer[0] = '.';
            buffer[1] = 0;
            return;
        }

        // Root. Nothing to do.
        if (sep == buffer.begin()) {
            return;
        }

        // Trim filename
        buffer.erase(sep, end());
    }

    void trimExtension(void) {
        iterator dot = rfind('.');
        if (dot != buffer.end()) {
            buffer.erase(dot, end());
        }
    }

    void join(const String & other) {
        if (length() && end()[-1] != OS_DIR_SEP) {
            append(OS_DIR_SEP);
        }
        append(other.begin(), other.end());
    }
};


String getProcessName();
String getCurrentDir();

bool copyFile(const String &srcFileName, const String &dstFileName, bool override = true);

bool removeFile(const String &fileName);

int getTemporaryFile(const char* description, std::string& path);
std::string getTemporaryFilename(const char* description);

inline bool setSysfsFile(const char* name, const char* value)
{
    FILE* file = fopen(name, "w");
    bool success = true;
    if (file == NULL)
    {
        perror("fopen sysfs file");
        return false;
    }
    if(fwrite(value, strlen(value), 1, file) != 1) {
        fprintf(stderr, "Unable to write to sysfs file.\n");
        success = false;
    }
    fclose(file);
    return success;
}

inline std::vector<std::string> splitString(const char* s, char delimiter)
{
    std::vector<std::string> ret;
    std::stringstream f(s);
    std::string str;
    while (std::getline(f, str, delimiter)) {
        ret.push_back(str);
    }
    return ret;
}

} /* namespace os */

#endif /* _OS_STRING_HPP_ */
